Virtual Reality For Cardiovascular Flow

Hemodynamics is closely related to the origin and development of atherosclerotic disease. In order to understand physiological and pathological behavior of human's cardiovascular system more deeply, it is necessary to research the hemodynamics in aorta. It is also necessary to take hemodynamic factors into surgical operations to prevent the dangerous hemodynamics for atherosclerosis. Nowadays, there have been a good many hemodynamic researches for atherosclerotic disease at some focal areas, but convenient and effective integrated system for hemodynamics analysis that is clinically relative has not been available.Based on the powerful FEM (finite element method) software ANSYS, VRCF (Virtual Reality of Cardiovascular Flow), an integrated set of software tools, is developed to research the hemodynamics at atherosclerotic focal areas. By a good graphic user interface (GUI), VRCF combines CAD modeling and 3D reconstruction of medical image, numerical simulation and flow visualization techniques to provide a convenient software environment for hemodynamics analysis. VRCF owns perfect data arrangement system, good GUI and optional environment set for path. The ultimate aim of VRCF is to provide a platform for surgical planning based on hemodynamics analysis.Many functions of VRCF are realized based on senior development of ANSYS. So, subsequently the process of how to realize hemodynamics simulation of cardiovascular system by senior development of ANSYS is discussed. By the APDL function of ANSYS, VRCF can analyze hemodynamics conveniently and automatically. By the UIDL function of ANSYS, VRCF is embedded in the graphicuser interface of ANSYS to be a part of ANSYS and to run whole system under a good GUI environment.As a clinical application of VRCF, the abdominal aorta is taken into consideration, and the hemodynamics of abdominal aorta is deeply analyzed. The conclusions is drawn that along the posterior wall in the infrarenal abdominal aorta, the flow velocity is low and a flow recirculation region is present in late systole and throughout diastole; At this recirculation region the shear stresses are low and oscillate; The atherosclerotic lesion appears at this region with high probability-of-occurrence.At last, medical image processing system, the important part of VRCF, is partly developed. The edge detection of medical image has been achieved, and the tentative work for 3D reconstruction has been done to help improve VRCF.